The eccentric Oh Hyun-jae was a peerless criminal profiler until a bomb planted by a serial killer took the life of his young fiancée, causing him to become a recluse. When a serial killer long thought dead returns to terrorize the city, rising star of the police, Hwang Ha-young, resolves to outwit the killer. To do so, she teams up with both Hyun-jae and the remarkable rookie cop Cha Soo-young, whose photographic memory may prove to be a powerful crime-fighting weapon.